A Coastguard boat is on its way to help two men in trouble on a yacht off the Northland coast, in waves nearly six metres high.
The men spent the night battling gale-force winds and huge waves.
They made a distress call just after 6pm yesterday after losing their steering and navigation systems while sailing their 12-metre yacht Beneteau between the Bay of Islands and Whangarei.
Coastguard duty officer Mark Leevers said several boats had tried to reach the pair, but had to turn back because of very rough sea conditions.
Coastguard operations manager Ray Burge said it had been a frustrating near-15-hour attempted rescue situation for both their own crews and the stranded yachties.
"These are frustrating circumstances ... but the weather conditions are such that a rescue attempt of both the people and the vessel at this stage is simply too dangerous.
"At this stage both onboard aren't in immediate danger but [are] understandably exhausted and ready to get into calm waters."
Burge said at the time their call was logged last night, winds were gusting over 40 knots off Tutukaka, there were waves just short of six metres, showers and poor visibility.
Tutukaka coastguard headed out to the boat's last known location about 7.30pm and the yacht was found 30 minutes later, having drifted further out to sea.
Despite their ordeal, the men were in relatively good spirits, Burge said.
However, trying to reach the men proved arduous for rescuers as the conditions were too rough to get close for both the Tutukaka crew and another from Whangarei.
"Given the vessel was now running low on diesel and had also run out of drinking water, Coastguard Radio advised that once they had reached a safe distance from shore, to cut their engine to preserve fuel and lay a sea anchor for the night."
The conditions deteriorated even further around midnight, and the boat's communications went down for about an hour, leaving the Coastguard to mull over an air rescue.
Their new location placed them 0.5nm offshore from Kauri Mountain, at the northern end of Ocean Beach.
A chopper was sent out from Whangarei at 2am but abysmal weather and lack of ambient light made visibility ineffective.
The yachties were advised the safest course was to head offshore as far as possible, deploy anchor and wait for daylight.
"We have to make sure that everyone - the two people on the yacht and our volunteers - are going to get home safely and last night the conditions were so severe, that this was an unlikely outcome."
The Circa rescue vessel was sent out again at first light today, with more diesel and water, and discovered waves up to four metres and winds of about 40 knots.
Given the conditions, the rescue was attempt was again postponed.
Burge said they were keeping in regular contact with the men who were doing well, despite their predicament.
"The yacht will continue to circle out at sea until conditions are reassessed this afternoon. A rescue helicopter continues to be on standby should the situation arise where the two people are required to abandon the vessel."
He hoped conditions would calm this afternoon.